diff options
| author | Andrew Jones <drjones@redhat.com> | 2020-01-30 16:02:06 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2020-01-30 16:02:06 +0000 |
| commit | e5ac4200b4cddf44df9adbef677af0d1f1c579c6 (patch) | |
| tree | 5637c03cc1e04a6e25841a29f1c24de550f86346 /target/arm/kvm_arm.h | |
| parent | 789a35efb583464f9fcd5d871a7fd6164318bb91 (diff) | |
target/arm/kvm: Implement virtual time adjustment
When a VM is stopped (such as when it's paused) guest virtual time
should stop counting. Otherwise, when the VM is resumed it will
experience time jumps and its kernel may report soft lockups. Not
counting virtual time while the VM is stopped has the side effect
of making the guest's time appear to lag when compared with real
time, and even with time derived from the physical counter. For
this reason, this change, which is enabled by default, comes with
a KVM CPU feature allowing it to be disabled, restoring legacy
behavior.
This patch only provides the implementation of the virtual time
adjustment. A subsequent patch will provide the CPU property
allowing the change to be enabled and disabled.
Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-6-drjones@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/kvm_arm.h')
| -rw-r--r-- | target/arm/kvm_arm.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h index b48a9c9557..01a9a18278 100644 --- a/target/arm/kvm_arm.h +++ b/target/arm/kvm_arm.h @@ -128,6 +128,23 @@ bool write_list_to_kvmstate(ARMCPU *cpu, int level); bool write_kvmstate_to_list(ARMCPU *cpu); /** + * kvm_arm_cpu_pre_save: + * @cpu: ARMCPU + * + * Called after write_kvmstate_to_list() from cpu_pre_save() to update + * the cpreg list with KVM CPU state. + */ +void kvm_arm_cpu_pre_save(ARMCPU *cpu); + +/** + * kvm_arm_cpu_post_load: + * @cpu: ARMCPU + * + * Called from cpu_post_load() to update KVM CPU state from the cpreg list. + */ +void kvm_arm_cpu_post_load(ARMCPU *cpu); + +/** * kvm_arm_reset_vcpu: * @cpu: ARMCPU * @@ -292,6 +309,24 @@ int kvm_arm_sync_mpstate_to_kvm(ARMCPU *cpu); */ int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu); +/** + * kvm_arm_get_virtual_time: + * @cs: CPUState + * + * Gets the VCPU's virtual counter and stores it in the KVM CPU state. + */ +void kvm_arm_get_virtual_time(CPUState *cs); + +/** + * kvm_arm_put_virtual_time: + * @cs: CPUState + * + * Sets the VCPU's virtual counter to the value stored in the KVM CPU state. + */ +void kvm_arm_put_virtual_time(CPUState *cs); + +void kvm_arm_vm_state_change(void *opaque, int running, RunState state); + int kvm_arm_vgic_probe(void); void kvm_arm_pmu_set_irq(CPUState *cs, int irq); @@ -339,6 +374,9 @@ static inline void kvm_arm_pmu_set_irq(CPUState *cs, int irq) {} static inline void kvm_arm_pmu_init(CPUState *cs) {} static inline void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map) {} + +static inline void kvm_arm_get_virtual_time(CPUState *cs) {} +static inline void kvm_arm_put_virtual_time(CPUState *cs) {} #endif static inline const char *gic_class_name(void) |